The present invention relates to itaconamide, N-substituted itaconamides, and a method of preparing same.
Itaconamide, which has the structure ##STR2## has been reported as being capable of preparation by ammonolysis of either dimethylitaconate or diethylitaconate. O. Strecker, Chem. Ber., 15, 1640 (1882), reports the synthesis of itaconamide by this method in an aqueous medium, the product having a melting point of 192.degree. C. British Pat. No. 917,958, published Feb. 13, 1963, also purports to prepare itaconamide by this method, employing substantially dry gaseous ammonia in the presence of certain substantially dry alkanols. The reported melting point of the product is 193.degree.-194.degree. C. The latter procedure was also employed by S. Ishida et al., J. Polym. Sci.: Part A-1, 5, 689 (1967) to produce "itaconic diamide" having a melting point of 195.4.degree.-196.5.degree. C.
It has been shown that the reaction of dimethyl- or diethylitaconate with ammonia does not produce itaconamide. Instead, the reaction has been shown to produce 2-pyrrolidone-4-carboxylic acid amide, ##STR3## which has a melting point of about 193.degree.-195.degree. C. Scarborough et al., J. Org. Chem., 26, 4955 (1961), report the production of this cyclic compound upon reaction of anhydrous ammonia with dimethylitaconate in absolute methanol. Hiroyoshi, J. Chem. Soc. Jap., vol. 69, No. 7, 1416, (1966), confirms this result for reactions conducted in both aqueous and alcoholic media. Further reference to the production of 2-pyrrolidone-4-carboxylic acid amide by the reaction of dimethyl- or diethylitaconate with ammonia is found in Kirk-Othmer, Encyclopedia of Chemical Technology, 3rd ed., vol. 13, John Wiley and Sons, New York, (1970) at p. 866 and Tate, Itaconic Acid, Itaconic Esters, and Related Compounds, High Polymers, vol. 24, Part 1, E. Leonard Ed., John Wiley and Sons, New York (1970) at pp. 210-211.
German OLS No. 2,422,375, opened to public inspection Nov. 28, 1974, purports to prepare itaconic acid and certain of its derivatives, including itaconamide. Repeated attempts by the present applicants to apply the method of the patent to the preparation of itaconamide were unsuccessful.
Patents which refer to itaconamide as a copolymerizable monomers are U.S. Pat. Nos. 2,531,408; 2,794,787; and 3,239,491; British Pat. Nos. 1,001,666; 1,002,343; 1,063,573; 1,167,161; and 1,167,162; German OLS No. 2,228,063; and French Pat. No. 1,421,926. None of the cited patents provides a method of preparing itaconamide, indicates procedures by which the compound may have been prepared, or provides any characterization of the compound.